The article “An efficient multimedia distribution framework for Internet video” by Jia Yao, Jozsef Vass, Yan Huang and Xinhua Zhuang, published in the journal Image and Video Communications and Processing 2000—Proceedings of SPIE Vol. 3974, describes a transmission system in which the receiver decides whether or not to transmit a retransmission request relating to a lost packet while taking account in particular of the importance of said lost packet.
This article does not define the idea of the importance of a packet, and does not describe the manner in which the receiver determines the importance of a lost packet.
A first object of the invention is to present a mechanism allowing the receiver to determine an importance level associated with a lost packet.
A second object of the invention is to present several ways of defining the importance level of a packet.